1 /*
2 * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotArtifactFinder.hpp"
26 #include "cds/aotCacheAccess.hpp"
27 #include "cds/aotClassInitializer.hpp"
28 #include "cds/aotClassLocation.hpp"
29 #include "cds/aotConstantPoolResolver.hpp"
30 #include "cds/aotLogging.hpp"
31 #include "cds/aotMetaspace.hpp"
32 #include "cds/aotReferenceObjSupport.hpp"
33 #include "cds/archiveBuilder.hpp"
34 #include "cds/archiveHeapLoader.hpp"
35 #include "cds/archiveHeapWriter.hpp"
36 #include "cds/archiveUtils.hpp"
37 #include "cds/cdsConfig.hpp"
38 #include "cds/cdsEnumKlass.hpp"
39 #include "cds/cdsHeapVerifier.hpp"
40 #include "cds/heapShared.hpp"
41 #include "cds/regeneratedClasses.hpp"
42 #include "classfile/classLoaderData.hpp"
43 #include "classfile/javaClasses.inline.hpp"
44 #include "classfile/modules.hpp"
45 #include "classfile/stringTable.hpp"
46 #include "classfile/symbolTable.hpp"
47 #include "classfile/systemDictionary.hpp"
48 #include "classfile/systemDictionaryShared.hpp"
49 #include "classfile/vmClasses.hpp"
50 #include "classfile/vmSymbols.hpp"
51 #include "gc/shared/collectedHeap.hpp"
52 #include "gc/shared/gcLocker.hpp"
53 #include "gc/shared/gcVMOperations.hpp"
54 #include "logging/log.hpp"
55 #include "logging/logStream.hpp"
56 #include "memory/iterator.inline.hpp"
57 #include "memory/resourceArea.hpp"
58 #include "memory/universe.hpp"
59 #include "oops/compressedOops.inline.hpp"
60 #include "oops/fieldStreams.inline.hpp"
61 #include "oops/objArrayOop.inline.hpp"
62 #include "oops/oop.inline.hpp"
63 #include "oops/oopHandle.inline.hpp"
64 #include "oops/typeArrayOop.inline.hpp"
65 #include "prims/jvmtiExport.hpp"
66 #include "runtime/arguments.hpp"
67 #include "runtime/fieldDescriptor.inline.hpp"
68 #include "runtime/init.hpp"
69 #include "runtime/javaCalls.hpp"
70 #include "runtime/mutexLocker.hpp"
71 #include "runtime/safepointVerifiers.hpp"
72 #include "utilities/bitMap.inline.hpp"
73 #include "utilities/copy.hpp"
74 #if INCLUDE_G1GC
75 #include "gc/g1/g1CollectedHeap.hpp"
76 #endif
77
78 #if INCLUDE_CDS_JAVA_HEAP
79
80 struct ArchivableStaticFieldInfo {
81 const char* klass_name;
82 const char* field_name;
83 InstanceKlass* klass;
84 int offset;
85 BasicType type;
86
87 ArchivableStaticFieldInfo(const char* k, const char* f)
88 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {}
89
90 bool valid() {
91 return klass_name != nullptr;
92 }
93 };
94
95 class HeapShared::ContextMark : public StackObj {
96 ResourceMark rm;
97 public:
98 ContextMark(const char* c) : rm{} {
99 _context->push(c);
100 }
101 ~ContextMark() {
102 _context->pop();
103 }
104 };
105
106 DumpedInternedStrings *HeapShared::_dumped_interned_strings = nullptr;
107
108 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
109 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
110 size_t HeapShared::_total_obj_count;
111 size_t HeapShared::_total_obj_size;
112
113 #ifndef PRODUCT
114 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
115 static Array<char>* _archived_ArchiveHeapTestClass = nullptr;
116 static const char* _test_class_name = nullptr;
117 static Klass* _test_class = nullptr;
118 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr;
119 #endif
120
121
122 //
123 // If you add new entries to the following tables, you should know what you're doing!
124 //
125
126 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = {
127 {"java/lang/Integer$IntegerCache", "archivedCache"},
128 {"java/lang/Long$LongCache", "archivedCache"},
129 {"java/lang/Byte$ByteCache", "archivedCache"},
130 {"java/lang/Short$ShortCache", "archivedCache"},
131 {"java/lang/Character$CharacterCache", "archivedCache"},
132 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
133 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
134 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
135 {"java/util/ImmutableCollections", "archivedObjects"},
136 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
137 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
138 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
139 {"java/lang/reflect/Proxy$ProxyBuilder", "archivedData"}, // FIXME -- requires AOTClassLinking
140
141 #ifndef PRODUCT
142 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass
143 #endif
144 {nullptr, nullptr},
145 };
146
147 // full module graph
148 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = {
149 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
150 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD},
151 {"java/lang/Module$ArchivedData", "archivedData"},
152 {nullptr, nullptr},
153 };
154
155 KlassSubGraphInfo* HeapShared::_dump_time_special_subgraph;
156 ArchivedKlassSubGraphInfoRecord* HeapShared::_run_time_special_subgraph;
157 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_pending_roots = nullptr;
158 GrowableArrayCHeap<const char*, mtClassShared>* HeapShared::_context = nullptr;
159 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_root_segments = nullptr;
160 int HeapShared::_root_segment_max_size_elems;
161 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1];
162 MetaspaceObjToOopHandleTable* HeapShared::_scratch_objects_table = nullptr;
163
164 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
165 for (int i = 0; fields[i].valid(); i++) {
166 if (fields[i].klass == ik) {
167 return true;
168 }
169 }
170 return false;
171 }
172
173 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
174 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
175 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
176 }
177
178 oop HeapShared::CachedOopInfo::orig_referrer() const {
179 return _orig_referrer.resolve();
180 }
181
182 void HeapShared::rehash_archived_object_cache() {
183 if (!CDSConfig::is_dumping_heap()) {
184 return;
185 }
186 assert(SafepointSynchronize::is_at_safepoint() ||
187 JavaThread::current()->is_in_no_safepoint_scope(), "sanity");
188
189 ArchivedObjectCache* new_cache =
190 new (mtClass)ArchivedObjectCache(archived_object_cache()->table_size(), MAX_TABLE_SIZE);
191
192 archived_object_cache()->iterate_all([&](OopHandle o, CachedOopInfo& info) {
193 new_cache->put_when_absent(o, info);
194 });
195
196 delete _archived_object_cache;
197 _archived_object_cache = new_cache;
198 }
199
200 unsigned HeapShared::oop_hash(oop const& p) {
201 assert(SafepointSynchronize::is_at_safepoint() ||
202 JavaThread::current()->is_in_no_safepoint_scope(), "sanity");
203 // Do not call p->identity_hash() as that will update the
204 // object header.
205 return primitive_hash(cast_from_oop<intptr_t>(p));
206 }
207
208 unsigned int HeapShared::oop_handle_hash_raw(const OopHandle& oh) {
209 return oop_hash(oh.resolve());
210 }
211
212 unsigned int HeapShared::oop_handle_hash(const OopHandle& oh) {
213 oop o = oh.resolve();
214 if (o == nullptr) {
215 return 0;
216 } else {
217 return o->identity_hash();
218 }
219 }
220
221 bool HeapShared::oop_handle_equals(const OopHandle& a, const OopHandle& b) {
222 return a.resolve() == b.resolve();
223 }
224
225 static void reset_states(oop obj, TRAPS) {
226 Handle h_obj(THREAD, obj);
227 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
228 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
229 Symbol* method_sig = vmSymbols::void_method_signature();
230
231 while (klass != nullptr) {
232 Method* method = klass->find_method(method_name, method_sig);
233 if (method != nullptr) {
234 assert(method->is_private(), "must be");
235 if (log_is_enabled(Debug, aot)) {
236 ResourceMark rm(THREAD);
237 log_debug(aot)(" calling %s", method->name_and_sig_as_C_string());
238 }
239 JavaValue result(T_VOID);
240 JavaCalls::call_special(&result, h_obj, klass,
241 method_name, method_sig, CHECK);
242 }
243 klass = klass->super();
244 }
245 }
246
247 void HeapShared::reset_archived_object_states(TRAPS) {
248 assert(CDSConfig::is_dumping_heap(), "dump-time only");
249 log_debug(aot)("Resetting platform loader");
250 reset_states(SystemDictionary::java_platform_loader(), CHECK);
251 log_debug(aot)("Resetting system loader");
252 reset_states(SystemDictionary::java_system_loader(), CHECK);
253
254 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
255 // directly used for class loading, but rather is used by the core library
256 // to keep track of resources, etc, loaded by the null class loader.
257 //
258 // Note, this object is non-null, and is not the same as
259 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
260 // which is null.
261 log_debug(aot)("Resetting boot loader");
262 JavaValue result(T_OBJECT);
263 JavaCalls::call_static(&result,
264 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
265 vmSymbols::bootLoader_name(),
266 vmSymbols::void_BuiltinClassLoader_signature(),
267 CHECK);
268 Handle boot_loader(THREAD, result.get_oop());
269 reset_states(boot_loader(), CHECK);
270 }
271
272 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
273
274 bool HeapShared::has_been_archived(oop obj) {
275 assert(CDSConfig::is_dumping_heap(), "dump-time only");
276 OopHandle oh(&obj);
277 return archived_object_cache()->get(oh) != nullptr;
278 }
279
280 int HeapShared::append_root(oop obj) {
281 assert(CDSConfig::is_dumping_heap(), "dump-time only");
282 if (obj != nullptr) {
283 assert(has_been_archived(obj), "must be");
284 }
285 // No GC should happen since we aren't scanning _pending_roots.
286 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
287
288 OopHandle oh(Universe::vm_global(), obj);
289 return _pending_roots->append(oh);
290 }
291
292 objArrayOop HeapShared::root_segment(int segment_idx) {
293 if (CDSConfig::is_dumping_heap() && !CDSConfig::is_dumping_final_static_archive()) {
294 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
295 } else {
296 assert(CDSConfig::is_using_archive(), "must be");
297 }
298
299 objArrayOop segment = (objArrayOop)_root_segments->at(segment_idx).resolve();
300 assert(segment != nullptr, "should have been initialized");
301 return segment;
302 }
303
304 class OrigToScratchObjectTable: public HashTable<OopHandle, OopHandle,
305 36137, // prime number
306 AnyObj::C_HEAP,
307 mtClassShared,
308 HeapShared::oop_handle_hash,
309 HeapShared::oop_handle_equals> {};
310
311 static OrigToScratchObjectTable* _orig_to_scratch_object_table = nullptr;
312
313 void HeapShared::track_scratch_object(oop orig_obj, oop scratch_obj) {
314 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
315 if (_orig_to_scratch_object_table == nullptr) {
316 _orig_to_scratch_object_table = new (mtClass)OrigToScratchObjectTable();
317 }
318
319 OopHandle orig_h(Universe::vm_global(), orig_obj);
320 OopHandle scratch_h(Universe::vm_global(), scratch_obj);
321 _orig_to_scratch_object_table->put_when_absent(orig_h, scratch_h);
322 }
323
324 oop HeapShared::orig_to_scratch_object(oop orig_obj) {
325 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
326 if (_orig_to_scratch_object_table != nullptr) {
327 OopHandle orig(&orig_obj);
328 OopHandle* v = _orig_to_scratch_object_table->get(orig);
329 if (v != nullptr) {
330 return v->resolve();
331 }
332 }
333 return nullptr;
334 }
335
336 // Permanent oops are used to support AOT-compiled methods, which may have in-line references
337 // to Strings and MH oops.
338 //
339 // At runtime, these oops are stored in _runtime_permanent_oops (which keeps them alive forever)
340 // and are accssed vis AOTCacheAccess::get_archived_object(int).
341 struct PermanentOopInfo {
342 int _index; // Gets assigned only if HeapShared::get_archived_object_permanent_index() has been called on the object
343 int _heap_offset; // Offset of the object from the bottom of the archived heap.
344 PermanentOopInfo(int index, int heap_offset) : _index(index), _heap_offset(heap_offset) {}
345 };
346
347 class PermanentOopTable: public HashTable<OopHandle, PermanentOopInfo,
348 36137, // prime number
349 AnyObj::C_HEAP,
350 mtClassShared,
351 HeapShared::oop_handle_hash,
352 HeapShared::oop_handle_equals> {};
353
354 static int _dumptime_permanent_oop_count = 0;
355 static PermanentOopTable* _dumptime_permanent_oop_table = nullptr;
356 static GrowableArrayCHeap<OopHandle, mtClassShared>* _runtime_permanent_oops = nullptr;
357
358 // ArchiveHeapWriter adds each archived heap object to _dumptime_permanent_oop_table,
359 // so we can remember their offset (from the bottom of the archived heap).
360 void HeapShared::add_to_permanent_oop_table(oop obj, int offset) {
361 assert_at_safepoint();
362 if (_dumptime_permanent_oop_table == nullptr) {
363 _dumptime_permanent_oop_table = new (mtClass)PermanentOopTable();
364 }
365
366 PermanentOopInfo info(-1, offset);
367 OopHandle oh(Universe::vm_global(), obj);
368 _dumptime_permanent_oop_table->put_when_absent(oh, info);
369 }
370
371 // A permanent index is assigned to an archived object ONLY when
372 // the AOT compiler calls this function.
373 int HeapShared::get_archived_object_permanent_index(oop obj) {
374 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
375
376 if (!CDSConfig::is_dumping_heap()) {
377 return -1; // Called by the Leyden old workflow
378 }
379 if (_dumptime_permanent_oop_table == nullptr) {
380 return -1;
381 }
382
383 if (_orig_to_scratch_object_table != nullptr) {
384 OopHandle orig(&obj);
385 OopHandle* v = _orig_to_scratch_object_table->get(orig);
386 if (v != nullptr) {
387 obj = v->resolve();
388 }
389 }
390
391 OopHandle tmp(&obj);
392 PermanentOopInfo* info = _dumptime_permanent_oop_table->get(tmp);
393 if (info == nullptr) {
394 return -1;
395 } else {
396 if (info->_index < 0) {
397 info->_index = _dumptime_permanent_oop_count++;
398 }
399 return info->_index;
400 }
401 }
402
403 oop HeapShared::get_archived_object(int permanent_index) {
404 assert(permanent_index >= 0, "sanity");
405 assert(ArchiveHeapLoader::is_in_use(), "sanity");
406 assert(_runtime_permanent_oops != nullptr, "sanity");
407
408 return _runtime_permanent_oops->at(permanent_index).resolve();
409 }
410
411 // Remember all archived heap objects that have a permanent index.
412 // table[i] = offset of oop whose permanent index is i.
413 void CachedCodeDirectoryInternal::dumptime_init_internal() {
414 const int count = _dumptime_permanent_oop_count;
415 if (count == 0) {
416 // Avoid confusing CDS code with zero-sized tables, just return.
417 log_info(cds)("No permanent oops");
418 _permanent_oop_count = count;
419 _permanent_oop_offsets = nullptr;
420 return;
421 }
422
423 int* table = (int*)AOTCacheAccess::allocate_aot_code_region(count * sizeof(int));
424 for (int i = 0; i < count; i++) {
425 table[count] = -1;
426 }
427 _dumptime_permanent_oop_table->iterate([&](OopHandle o, PermanentOopInfo& info) {
428 int index = info._index;
429 if (index >= 0) {
430 assert(index < count, "sanity");
431 table[index] = info._heap_offset;
432 }
433 return true; // continue
434 });
435
436 for (int i = 0; i < count; i++) {
437 assert(table[i] >= 0, "must be");
438 }
439
440 log_info(cds)("Dumped %d permanent oops", count);
441
442 _permanent_oop_count = count;
443 AOTCacheAccess::set_pointer(&_permanent_oop_offsets, table);
444 }
445
446 // This is called during the bootstrap of the production run, before any GC can happen.
447 // Record each permanent oop in a OopHandle for GC safety.
448 void CachedCodeDirectoryInternal::runtime_init_internal() {
449 int count = _permanent_oop_count;
450 int* table = _permanent_oop_offsets;
451 _runtime_permanent_oops = new GrowableArrayCHeap<OopHandle, mtClassShared>();
452 for (int i = 0; i < count; i++) {
453 oop obj = ArchiveHeapLoader::oop_from_offset(table[i]);
454 OopHandle oh(Universe::vm_global(), obj);
455 _runtime_permanent_oops->append(oh);
456 }
457 };
458
459 void HeapShared::get_segment_indexes(int idx, int& seg_idx, int& int_idx) {
460 assert(_root_segment_max_size_elems > 0, "sanity");
461
462 // Try to avoid divisions for the common case.
463 if (idx < _root_segment_max_size_elems) {
464 seg_idx = 0;
465 int_idx = idx;
466 } else {
467 seg_idx = idx / _root_segment_max_size_elems;
468 int_idx = idx % _root_segment_max_size_elems;
469 }
470
471 assert(idx == seg_idx * _root_segment_max_size_elems + int_idx,
472 "sanity: %d index maps to %d segment and %d internal", idx, seg_idx, int_idx);
473 }
474
475 // Returns an objArray that contains all the roots of the archived objects
476 oop HeapShared::get_root(int index, bool clear) {
477 assert(index >= 0, "sanity");
478 assert(!CDSConfig::is_dumping_heap() && CDSConfig::is_using_archive(), "runtime only");
479 assert(!_root_segments->is_empty(), "must have loaded shared heap");
480 int seg_idx, int_idx;
481 get_segment_indexes(index, seg_idx, int_idx);
482 oop result = root_segment(seg_idx)->obj_at(int_idx);
483 if (clear) {
484 clear_root(index);
485 }
486 return result;
487 }
488
489 void HeapShared::clear_root(int index) {
490 assert(index >= 0, "sanity");
491 assert(CDSConfig::is_using_archive(), "must be");
492 if (ArchiveHeapLoader::is_in_use()) {
493 int seg_idx, int_idx;
494 get_segment_indexes(index, seg_idx, int_idx);
495 if (log_is_enabled(Debug, aot, heap)) {
496 oop old = root_segment(seg_idx)->obj_at(int_idx);
497 log_debug(aot, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old));
498 }
499 root_segment(seg_idx)->obj_at_put(int_idx, nullptr);
500 }
501 }
502
503 bool HeapShared::archive_object(oop obj, oop referrer, KlassSubGraphInfo* subgraph_info) {
504 assert(CDSConfig::is_dumping_heap(), "dump-time only");
505
506 assert(!obj->is_stackChunk(), "do not archive stack chunks");
507 if (has_been_archived(obj)) {
508 return true;
509 }
510
511 if (ArchiveHeapWriter::is_too_large_to_archive(obj->size())) {
512 log_debug(aot, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: %zu",
513 p2i(obj), obj->size());
514 debug_trace();
515 return false;
516 } else {
517 count_allocation(obj->size());
518 ArchiveHeapWriter::add_source_obj(obj);
519 CachedOopInfo info = make_cached_oop_info(obj, referrer);
520
521 OopHandle oh(Universe::vm_global(), obj);
522 archived_object_cache()->put_when_absent(oh, info);
523 archived_object_cache()->maybe_grow();
524 mark_native_pointers(obj);
525
526 Klass* k = obj->klass();
527 if (k->is_instance_klass()) {
528 // Whenever we see a non-array Java object of type X, we mark X to be aot-initialized.
529 // This ensures that during the production run, whenever Java code sees a cached object
530 // of type X, we know that X is already initialized. (see TODO comment below ...)
531
532 if (InstanceKlass::cast(k)->is_enum_subclass()
533 // We can't rerun <clinit> of enum classes (see cdsEnumKlass.cpp) so
534 // we must store them as AOT-initialized.
535 || (subgraph_info == _dump_time_special_subgraph))
536 // TODO: we do this only for the special subgraph for now. Extending this to
537 // other subgraphs would require more refactoring of the core library (such as
538 // move some initialization logic into runtimeSetup()).
539 //
540 // For the other subgraphs, we have a weaker mechanism to ensure that
541 // all classes in a subgraph are initialized before the subgraph is programmatically
542 // returned from jdk.internal.misc.CDS::initializeFromArchive().
543 // See HeapShared::initialize_from_archived_subgraph().
544 {
545 AOTArtifactFinder::add_aot_inited_class(InstanceKlass::cast(k));
546 }
547
548 if (java_lang_Class::is_instance(obj)) {
549 Klass* mirror_k = java_lang_Class::as_Klass(obj);
550 if (mirror_k != nullptr) {
551 AOTArtifactFinder::add_cached_class(mirror_k);
552 }
553 } else if (java_lang_invoke_ResolvedMethodName::is_instance(obj)) {
554 Method* m = java_lang_invoke_ResolvedMethodName::vmtarget(obj);
555 if (m != nullptr) {
556 if (RegeneratedClasses::has_been_regenerated(m)) {
557 m = RegeneratedClasses::get_regenerated_object(m);
558 }
559 InstanceKlass* method_holder = m->method_holder();
560 AOTArtifactFinder::add_cached_class(method_holder);
561 }
562 }
563 }
564
565 if (log_is_enabled(Debug, aot, heap)) {
566 ResourceMark rm;
567 LogTarget(Debug, aot, heap) log;
568 LogStream out(log);
569 out.print("Archived heap object " PTR_FORMAT " : %s ",
570 p2i(obj), obj->klass()->external_name());
571 if (java_lang_Class::is_instance(obj)) {
572 Klass* k = java_lang_Class::as_Klass(obj);
573 if (k != nullptr) {
574 out.print("%s", k->external_name());
575 } else {
576 out.print("primitive");
577 }
578 }
579 out.cr();
580 }
581
582 return true;
583 }
584 }
585
586 class MetaspaceObjToOopHandleTable: public HashTable<MetaspaceObj*, OopHandle,
587 36137, // prime number
588 AnyObj::C_HEAP,
589 mtClassShared> {
590 public:
591 oop get_oop(MetaspaceObj* ptr) {
592 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
593 OopHandle* handle = get(ptr);
594 if (handle != nullptr) {
595 return handle->resolve();
596 } else {
597 return nullptr;
598 }
599 }
600 void set_oop(MetaspaceObj* ptr, oop o) {
601 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
602 OopHandle handle(Universe::vm_global(), o);
603 bool is_new = put(ptr, handle);
604 assert(is_new, "cannot set twice");
605 }
606 void remove_oop(MetaspaceObj* ptr) {
607 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
608 OopHandle* handle = get(ptr);
609 if (handle != nullptr) {
610 handle->release(Universe::vm_global());
611 remove(ptr);
612 }
613 }
614 };
615
616 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
617 if (SystemDictionaryShared::is_builtin_loader(src->pool_holder()->class_loader_data())) {
618 _scratch_objects_table->set_oop(src, dest);
619 }
620 }
621
622 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
623 return (objArrayOop)_scratch_objects_table->get_oop(src);
624 }
625
626 void HeapShared::init_dumping() {
627 _scratch_objects_table = new (mtClass)MetaspaceObjToOopHandleTable();
628 _pending_roots = new GrowableArrayCHeap<OopHandle, mtClassShared>(500);
629 }
630
631 void HeapShared::init_scratch_objects_for_basic_type_mirrors(TRAPS) {
632 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
633 BasicType bt = (BasicType)i;
634 if (!is_reference_type(bt)) {
635 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
636 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
637 track_scratch_object(Universe::java_mirror(bt), m);
638 }
639 }
640 }
641
642 // Given java_mirror that represents a (primitive or reference) type T,
643 // return the "scratch" version that represents the same type T.
644 // Note that if java_mirror will be returned if it's already a
645 // scratch mirror.
646 //
647 // See java_lang_Class::create_scratch_mirror() for more info.
648 oop HeapShared::scratch_java_mirror(oop java_mirror) {
649 assert(java_lang_Class::is_instance(java_mirror), "must be");
650
651 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
652 BasicType bt = (BasicType)i;
653 if (!is_reference_type(bt)) {
654 if (_scratch_basic_type_mirrors[i].resolve() == java_mirror) {
655 return java_mirror;
656 }
657 }
658 }
659
660 if (java_lang_Class::is_primitive(java_mirror)) {
661 return scratch_java_mirror(java_lang_Class::as_BasicType(java_mirror));
662 } else {
663 return scratch_java_mirror(java_lang_Class::as_Klass(java_mirror));
664 }
665 }
666
667 oop HeapShared::scratch_java_mirror(BasicType t) {
668 assert((uint)t < T_VOID+1, "range check");
669 assert(!is_reference_type(t), "sanity");
670 return _scratch_basic_type_mirrors[t].resolve();
671 }
672
673 oop HeapShared::scratch_java_mirror(Klass* k) {
674 return _scratch_objects_table->get_oop(k);
675 }
676
677 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
678 track_scratch_object(k->java_mirror(), mirror);
679 _scratch_objects_table->set_oop(k, mirror);
680 }
681
682 void HeapShared::remove_scratch_objects(Klass* k) {
683 // Klass is being deallocated. Java mirror can still be alive, and it should not
684 // point to dead klass. We need to break the link from mirror to the Klass.
685 // See how InstanceKlass::deallocate_contents does it for normal mirrors.
686 oop mirror = _scratch_objects_table->get_oop(k);
687 if (mirror != nullptr) {
688 java_lang_Class::set_klass(mirror, nullptr);
689 }
690 _scratch_objects_table->remove_oop(k);
691 if (k->is_instance_klass()) {
692 _scratch_objects_table->remove(InstanceKlass::cast(k)->constants());
693 }
694 if (mirror != nullptr) {
695 OopHandle tmp(&mirror);
696 OopHandle* v = _orig_to_scratch_object_table->get(tmp);
697 if (v != nullptr) {
698 oop scratch_mirror = v->resolve();
699 java_lang_Class::set_klass(scratch_mirror, nullptr);
700 _orig_to_scratch_object_table->remove(tmp);
701 }
702 }
703 }
704
705 //TODO: we eventually want a more direct test for these kinds of things.
706 //For example the JVM could record some bit of context from the creation
707 //of the klass, such as who called the hidden class factory. Using
708 //string compares on names is fragile and will break as soon as somebody
709 //changes the names in the JDK code. See discussion in JDK-8342481 for
710 //related ideas about marking AOT-related classes.
711 bool HeapShared::is_lambda_form_klass(InstanceKlass* ik) {
712 return ik->is_hidden() &&
713 (ik->name()->starts_with("java/lang/invoke/LambdaForm$MH+") ||
714 ik->name()->starts_with("java/lang/invoke/LambdaForm$DMH+") ||
715 ik->name()->starts_with("java/lang/invoke/LambdaForm$BMH+") ||
716 ik->name()->starts_with("java/lang/invoke/LambdaForm$VH+"));
717 }
718
719 bool HeapShared::is_lambda_proxy_klass(InstanceKlass* ik) {
720 return ik->is_hidden() && (ik->name()->index_of_at(0, "$$Lambda+", 9) > 0);
721 }
722
723 bool HeapShared::is_string_concat_klass(InstanceKlass* ik) {
724 return ik->is_hidden() && ik->name()->starts_with("java/lang/String$$StringConcat");
725 }
726
727 bool HeapShared::is_archivable_hidden_klass(InstanceKlass* ik) {
728 return CDSConfig::is_dumping_method_handles() &&
729 (is_lambda_form_klass(ik) || is_lambda_proxy_klass(ik) || is_string_concat_klass(ik));
730 }
731
732
733 void HeapShared::copy_and_rescan_aot_inited_mirror(InstanceKlass* ik) {
734 ik->set_has_aot_initialized_mirror();
735
736 oop orig_mirror;
737 if (RegeneratedClasses::is_regenerated_object(ik)) {
738 InstanceKlass* orig_ik = RegeneratedClasses::get_original_object(ik);
739 precond(orig_ik->is_initialized());
740 orig_mirror = orig_ik->java_mirror();
741 } else {
742 precond(ik->is_initialized());
743 orig_mirror = ik->java_mirror();
744 }
745
746 oop m = scratch_java_mirror(ik);
747 int nfields = 0;
748 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
749 if (fs.access_flags().is_static()) {
750 fieldDescriptor& fd = fs.field_descriptor();
751 int offset = fd.offset();
752 switch (fd.field_type()) {
753 case T_OBJECT:
754 case T_ARRAY:
755 {
756 oop field_obj = orig_mirror->obj_field(offset);
757 m->obj_field_put(offset, field_obj);
758 if (field_obj != nullptr) {
759 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, field_obj);
760 assert(success, "sanity");
761 }
762 }
763 break;
764 case T_BOOLEAN:
765 m->bool_field_put(offset, orig_mirror->bool_field(offset));
766 break;
767 case T_BYTE:
768 m->byte_field_put(offset, orig_mirror->byte_field(offset));
769 break;
770 case T_SHORT:
771 m->short_field_put(offset, orig_mirror->short_field(offset));
772 break;
773 case T_CHAR:
774 m->char_field_put(offset, orig_mirror->char_field(offset));
775 break;
776 case T_INT:
777 m->int_field_put(offset, orig_mirror->int_field(offset));
778 break;
779 case T_LONG:
780 m->long_field_put(offset, orig_mirror->long_field(offset));
781 break;
782 case T_FLOAT:
783 m->float_field_put(offset, orig_mirror->float_field(offset));
784 break;
785 case T_DOUBLE:
786 m->double_field_put(offset, orig_mirror->double_field(offset));
787 break;
788 default:
789 ShouldNotReachHere();
790 }
791 nfields ++;
792 }
793 }
794
795 oop class_data = java_lang_Class::class_data(orig_mirror);
796 java_lang_Class::set_class_data(m, class_data);
797 if (class_data != nullptr) {
798 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, class_data);
799 assert(success, "sanity");
800 }
801
802 if (log_is_enabled(Debug, aot, init)) {
803 ResourceMark rm;
804 log_debug(aot, init)("copied %3d field(s) in aot-initialized mirror %s%s%s", nfields, ik->external_name(),
805 ik->is_hidden() ? " (hidden)" : "",
806 ik->is_enum_subclass() ? " (enum)" : "");
807 }
808 }
809
810 void HeapShared::copy_java_mirror(oop orig_mirror, oop scratch_m) {
811 // We need to retain the identity_hash, because it may have been used by some hashtables
812 // in the shared heap.
813 if (!orig_mirror->fast_no_hash_check()) {
814 intptr_t src_hash = orig_mirror->identity_hash();
815 if (UseCompactObjectHeaders) {
816 narrowKlass nk = CompressedKlassPointers::encode(orig_mirror->klass());
817 scratch_m->set_mark(markWord::prototype().set_narrow_klass(nk).copy_set_hash(src_hash));
818 } else {
819 scratch_m->set_mark(markWord::prototype().copy_set_hash(src_hash));
820 }
821 assert(scratch_m->mark().is_unlocked(), "sanity");
822
823 DEBUG_ONLY(intptr_t archived_hash = scratch_m->identity_hash());
824 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
825 }
826
827 Klass* k = java_lang_Class::as_Klass(orig_mirror); // is null Universe::void_mirror();
828 if (CDSConfig::is_dumping_reflection_data() &&
829 k != nullptr && k->is_instance_klass() &&
830 java_lang_Class::reflection_data(orig_mirror) != nullptr &&
831 AOTConstantPoolResolver::can_archive_reflection_data(InstanceKlass::cast(k))) {
832 java_lang_Class::set_reflection_data(scratch_m, java_lang_Class::reflection_data(orig_mirror));
833 }
834 }
835
836 static objArrayOop get_archived_resolved_references(InstanceKlass* src_ik) {
837 if (SystemDictionaryShared::is_builtin_loader(src_ik->class_loader_data())) {
838 objArrayOop rr = src_ik->constants()->resolved_references_or_null();
839 if (rr != nullptr && !ArchiveHeapWriter::is_too_large_to_archive(rr)) {
840 return HeapShared::scratch_resolved_references(src_ik->constants());
841 }
842 }
843 return nullptr;
844 }
845
846 void HeapShared::archive_strings() {
847 oop shared_strings_array = StringTable::init_shared_strings_array();
848 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, shared_strings_array);
849 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
850 StringTable::set_shared_strings_array_index(append_root(shared_strings_array));
851 }
852
853 int HeapShared::archive_exception_instance(oop exception) {
854 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, exception);
855 assert(success, "sanity");
856 return append_root(exception);
857 }
858
859 void HeapShared::mark_native_pointers(oop orig_obj) {
860 if (java_lang_Class::is_instance(orig_obj)) {
861 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset());
862 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::array_klass_offset());
863 } else if (java_lang_invoke_ResolvedMethodName::is_instance(orig_obj)) {
864 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_invoke_ResolvedMethodName::vmtarget_offset());
865 }
866 }
867
868 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
869 OopHandle oh(&src_obj);
870 CachedOopInfo* info = archived_object_cache()->get(oh);
871 assert(info != nullptr, "must be");
872 has_oop_pointers = info->has_oop_pointers();
873 has_native_pointers = info->has_native_pointers();
874 }
875
876 void HeapShared::set_has_native_pointers(oop src_obj) {
877 OopHandle oh(&src_obj);
878 CachedOopInfo* info = archived_object_cache()->get(oh);
879 assert(info != nullptr, "must be");
880 info->set_has_native_pointers();
881 }
882
883 // Between start_scanning_for_oops() and end_scanning_for_oops(), we discover all Java heap objects that
884 // should be stored in the AOT cache. The scanning is coordinated by AOTArtifactFinder.
885 void HeapShared::start_scanning_for_oops() {
886 {
887 NoSafepointVerifier nsv;
888
889 // The special subgraph doesn't belong to any class. We use Object_klass() here just
890 // for convenience.
891 _dump_time_special_subgraph = init_subgraph_info(vmClasses::Object_klass(), false);
892 _context = new GrowableArrayCHeap<const char*, mtClassShared>(250);
893
894 // Cache for recording where the archived objects are copied to
895 create_archived_object_cache();
896
897 if (UseCompressedOops || UseG1GC) {
898 aot_log_info(aot)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
899 UseCompressedOops ? p2i(CompressedOops::begin()) :
900 p2i((address)G1CollectedHeap::heap()->reserved().start()),
901 UseCompressedOops ? p2i(CompressedOops::end()) :
902 p2i((address)G1CollectedHeap::heap()->reserved().end()));
903 }
904
905 archive_subgraphs();
906 }
907
908 init_seen_objects_table();
909 Universe::archive_exception_instances();
910 }
911
912 void HeapShared::end_scanning_for_oops() {
913 archive_strings();
914 delete_seen_objects_table();
915 }
916
917 void HeapShared::write_heap(ArchiveHeapInfo *heap_info) {
918 {
919 NoSafepointVerifier nsv;
920 if (!SkipArchiveHeapVerification) {
921 CDSHeapVerifier::verify();
922 }
923 check_special_subgraph_classes();
924 }
925
926 StringTable::write_shared_table();
927 GrowableArrayCHeap<oop, mtClassShared>* roots = new GrowableArrayCHeap<oop, mtClassShared>(_pending_roots->length());
928 for (int i = 0; i < _pending_roots->length(); i++) {
929 roots->append(_pending_roots->at(i).resolve());
930 }
931 ArchiveHeapWriter::write(roots, heap_info);
932 delete roots;
933
934 ArchiveBuilder::OtherROAllocMark mark;
935 write_subgraph_info_table();
936 }
937
938 void HeapShared::scan_java_mirror(oop orig_mirror) {
939 oop m = scratch_java_mirror(orig_mirror);
940 if (m != nullptr) { // nullptr if for custom class loader
941 copy_java_mirror(orig_mirror, m);
942 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, m);
943 assert(success, "sanity");
944
945 oop extra;
946 if ((extra = java_lang_Class::reflection_data(m)) != nullptr) {
947 success = archive_reachable_objects_from(1, _dump_time_special_subgraph, extra);
948 assert(success, "sanity");
949 }
950 }
951 }
952
953 void HeapShared::scan_java_class(Klass* orig_k) {
954 scan_java_mirror(orig_k->java_mirror());
955
956 if (orig_k->is_instance_klass()) {
957 InstanceKlass* orig_ik = InstanceKlass::cast(orig_k);
958 orig_ik->constants()->prepare_resolved_references_for_archiving();
959 objArrayOop rr = get_archived_resolved_references(orig_ik);
960 if (rr != nullptr) {
961 bool success = HeapShared::archive_reachable_objects_from(1, _dump_time_special_subgraph, rr);
962 assert(success, "must be");
963 }
964 }
965 }
966
967 void HeapShared::archive_subgraphs() {
968 assert(CDSConfig::is_dumping_heap(), "must be");
969
970 archive_object_subgraphs(archive_subgraph_entry_fields,
971 false /* is_full_module_graph */);
972
973 if (CDSConfig::is_dumping_full_module_graph()) {
974 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
975 true /* is_full_module_graph */);
976 Modules::verify_archived_modules();
977 }
978 }
979
980 //
981 // Subgraph archiving support
982 //
983 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
984 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
985
986 // Get the subgraph_info for Klass k. A new subgraph_info is created if
987 // there is no existing one for k. The subgraph_info records the "buffered"
988 // address of the class.
989 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
990 assert(CDSConfig::is_dumping_heap(), "dump time only");
991 bool created;
992 KlassSubGraphInfo* info =
993 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(k, is_full_module_graph),
994 &created);
995 assert(created, "must not initialize twice");
996 return info;
997 }
998
999 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
1000 assert(CDSConfig::is_dumping_heap(), "dump time only");
1001 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
1002 assert(info != nullptr, "must have been initialized");
1003 return info;
1004 }
1005
1006 // Add an entry field to the current KlassSubGraphInfo.
1007 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
1008 assert(CDSConfig::is_dumping_heap(), "dump time only");
1009 if (_subgraph_entry_fields == nullptr) {
1010 _subgraph_entry_fields =
1011 new (mtClass) GrowableArray<int>(10, mtClass);
1012 }
1013 _subgraph_entry_fields->append(static_field_offset);
1014 _subgraph_entry_fields->append(HeapShared::append_root(v));
1015 }
1016
1017 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
1018 // Only objects of boot classes can be included in sub-graph.
1019 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
1020 assert(CDSConfig::is_dumping_heap(), "dump time only");
1021
1022 if (_subgraph_object_klasses == nullptr) {
1023 _subgraph_object_klasses =
1024 new (mtClass) GrowableArray<Klass*>(50, mtClass);
1025 }
1026
1027 if (_k == orig_k) {
1028 // Don't add the Klass containing the sub-graph to it's own klass
1029 // initialization list.
1030 return;
1031 }
1032
1033 if (orig_k->is_instance_klass()) {
1034 #ifdef ASSERT
1035 InstanceKlass* ik = InstanceKlass::cast(orig_k);
1036 if (CDSConfig::is_dumping_method_handles()) {
1037 // -XX:AOTInitTestClass must be used carefully in regression tests to
1038 // include only classes that are safe to aot-initialize.
1039 assert(ik->class_loader() == nullptr ||
1040 HeapShared::is_lambda_proxy_klass(ik) ||
1041 AOTClassInitializer::has_test_class(),
1042 "we can archive only instances of boot classes or lambda proxy classes");
1043 } else {
1044 assert(ik->class_loader() == nullptr, "must be boot class");
1045 }
1046 #endif
1047 // vmClasses::xxx_klass() are not updated, need to check
1048 // the original Klass*
1049 if (orig_k == vmClasses::String_klass() ||
1050 orig_k == vmClasses::Object_klass()) {
1051 // Initialized early during VM initialization. No need to be added
1052 // to the sub-graph object class list.
1053 return;
1054 }
1055 check_allowed_klass(InstanceKlass::cast(orig_k));
1056 } else if (orig_k->is_objArray_klass()) {
1057 Klass* abk = ObjArrayKlass::cast(orig_k)->bottom_klass();
1058 if (abk->is_instance_klass()) {
1059 assert(InstanceKlass::cast(abk)->defined_by_boot_loader(),
1060 "must be boot class");
1061 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
1062 }
1063 if (orig_k == Universe::objectArrayKlass()) {
1064 // Initialized early during Universe::genesis. No need to be added
1065 // to the list.
1066 return;
1067 }
1068 } else {
1069 assert(orig_k->is_typeArray_klass(), "must be");
1070 // Primitive type arrays are created early during Universe::genesis.
1071 return;
1072 }
1073
1074 if (log_is_enabled(Debug, aot, heap)) {
1075 if (!_subgraph_object_klasses->contains(orig_k)) {
1076 ResourceMark rm;
1077 log_debug(aot, heap)("Adding klass %s", orig_k->external_name());
1078 }
1079 }
1080
1081 _subgraph_object_klasses->append_if_missing(orig_k);
1082 _has_non_early_klasses |= is_non_early_klass(orig_k);
1083 }
1084
1085 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
1086 #ifndef PRODUCT
1087 if (AOTClassInitializer::has_test_class()) {
1088 // The tests can cache arbitrary types of objects.
1089 return;
1090 }
1091 #endif
1092
1093 if (ik->module()->name() == vmSymbols::java_base()) {
1094 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
1095 return;
1096 }
1097
1098 const char* lambda_msg = "";
1099 if (CDSConfig::is_dumping_method_handles()) {
1100 lambda_msg = ", or a lambda proxy class";
1101 if (HeapShared::is_lambda_proxy_klass(ik) &&
1102 (ik->class_loader() == nullptr ||
1103 ik->class_loader() == SystemDictionary::java_platform_loader() ||
1104 ik->class_loader() == SystemDictionary::java_system_loader())) {
1105 return;
1106 }
1107 }
1108
1109 #ifndef PRODUCT
1110 if (!ik->module()->is_named() && ik->package() == nullptr && ArchiveHeapTestClass != nullptr) {
1111 // This class is loaded by ArchiveHeapTestClass
1112 return;
1113 }
1114 const char* testcls_msg = ", or a test class in an unnamed package of an unnamed module";
1115 #else
1116 const char* testcls_msg = "";
1117 #endif
1118
1119 ResourceMark rm;
1120 log_error(aot, heap)("Class %s not allowed in archive heap. Must be in java.base%s%s",
1121 ik->external_name(), lambda_msg, testcls_msg);
1122 AOTMetaspace::unrecoverable_writing_error();
1123 }
1124
1125 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
1126 if (k->is_objArray_klass()) {
1127 k = ObjArrayKlass::cast(k)->bottom_klass();
1128 }
1129 if (k->is_instance_klass()) {
1130 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
1131 ResourceMark rm;
1132 log_info(aot, heap)("non-early: %s", k->external_name());
1133 return true;
1134 } else {
1135 return false;
1136 }
1137 } else {
1138 return false;
1139 }
1140 }
1141
1142 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
1143 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
1144 _k = ArchiveBuilder::get_buffered_klass(info->klass());
1145 _entry_field_records = nullptr;
1146 _subgraph_object_klasses = nullptr;
1147 _is_full_module_graph = info->is_full_module_graph();
1148
1149 if (_is_full_module_graph) {
1150 // Consider all classes referenced by the full module graph as early -- we will be
1151 // allocating objects of these classes during JVMTI early phase, so they cannot
1152 // be processed by (non-early) JVMTI ClassFileLoadHook
1153 _has_non_early_klasses = false;
1154 } else {
1155 _has_non_early_klasses = info->has_non_early_klasses();
1156 }
1157
1158 if (_has_non_early_klasses) {
1159 ResourceMark rm;
1160 log_info(aot, heap)(
1161 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
1162 _k->external_name());
1163 }
1164
1165 // populate the entry fields
1166 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
1167 if (entry_fields != nullptr) {
1168 int num_entry_fields = entry_fields->length();
1169 assert(num_entry_fields % 2 == 0, "sanity");
1170 _entry_field_records =
1171 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
1172 for (int i = 0 ; i < num_entry_fields; i++) {
1173 _entry_field_records->at_put(i, entry_fields->at(i));
1174 }
1175 }
1176
1177 // <recorded_klasses> has the Klasses of all the objects that are referenced by this subgraph.
1178 // Copy those that need to be explicitly initialized into <_subgraph_object_klasses>.
1179 GrowableArray<Klass*>* recorded_klasses = info->subgraph_object_klasses();
1180 if (recorded_klasses != nullptr) {
1181 // AOT-inited classes are automatically marked as "initialized" during bootstrap. When
1182 // programmatically loading a subgraph, we only need to explicitly initialize the classes
1183 // that are not aot-inited.
1184 int num_to_copy = 0;
1185 for (int i = 0; i < recorded_klasses->length(); i++) {
1186 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1187 if (!subgraph_k->has_aot_initialized_mirror()) {
1188 num_to_copy ++;
1189 }
1190 }
1191
1192 _subgraph_object_klasses = ArchiveBuilder::new_ro_array<Klass*>(num_to_copy);
1193 bool is_special = (_k == ArchiveBuilder::get_buffered_klass(vmClasses::Object_klass()));
1194 for (int i = 0, n = 0; i < recorded_klasses->length(); i++) {
1195 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1196 if (subgraph_k->has_aot_initialized_mirror()) {
1197 continue;
1198 }
1199 if (log_is_enabled(Info, aot, heap)) {
1200 ResourceMark rm;
1201 const char* owner_name = is_special ? "<special>" : _k->external_name();
1202 if (subgraph_k->is_instance_klass()) {
1203 InstanceKlass* src_ik = InstanceKlass::cast(ArchiveBuilder::current()->get_source_addr(subgraph_k));
1204 }
1205 log_info(aot, heap)(
1206 "Archived object klass %s (%2d) => %s",
1207 owner_name, n, subgraph_k->external_name());
1208 }
1209 _subgraph_object_klasses->at_put(n, subgraph_k);
1210 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(n));
1211 n++;
1212 }
1213 }
1214
1215 ArchivePtrMarker::mark_pointer(&_k);
1216 ArchivePtrMarker::mark_pointer(&_entry_field_records);
1217 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
1218 }
1219
1220 class HeapShared::CopyKlassSubGraphInfoToArchive : StackObj {
1221 CompactHashtableWriter* _writer;
1222 public:
1223 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
1224
1225 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
1226 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
1227 ArchivedKlassSubGraphInfoRecord* record = HeapShared::archive_subgraph_info(&info);
1228 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
1229 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
1230 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
1231 _writer->add(hash, delta);
1232 }
1233 return true; // keep on iterating
1234 }
1235 };
1236
1237 ArchivedKlassSubGraphInfoRecord* HeapShared::archive_subgraph_info(KlassSubGraphInfo* info) {
1238 ArchivedKlassSubGraphInfoRecord* record =
1239 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
1240 record->init(info);
1241 if (info == _dump_time_special_subgraph) {
1242 _run_time_special_subgraph = record;
1243 }
1244 return record;
1245 }
1246
1247 // Build the records of archived subgraph infos, which include:
1248 // - Entry points to all subgraphs from the containing class mirror. The entry
1249 // points are static fields in the mirror. For each entry point, the field
1250 // offset, and value are recorded in the sub-graph
1251 // info. The value is stored back to the corresponding field at runtime.
1252 // - A list of klasses that need to be loaded/initialized before archived
1253 // java object sub-graph can be accessed at runtime.
1254 void HeapShared::write_subgraph_info_table() {
1255 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
1256 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
1257 CompactHashtableStats stats;
1258
1259 _run_time_subgraph_info_table.reset();
1260
1261 CompactHashtableWriter writer(d_table->_count, &stats);
1262 CopyKlassSubGraphInfoToArchive copy(&writer);
1263 d_table->iterate(©);
1264 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
1265
1266 #ifndef PRODUCT
1267 if (ArchiveHeapTestClass != nullptr) {
1268 size_t len = strlen(ArchiveHeapTestClass) + 1;
1269 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
1270 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
1271 _archived_ArchiveHeapTestClass = array;
1272 }
1273 #endif
1274 if (log_is_enabled(Info, aot, heap)) {
1275 print_stats();
1276 }
1277 }
1278
1279 void HeapShared::add_root_segment(objArrayOop segment_oop) {
1280 assert(segment_oop != nullptr, "must be");
1281 assert(ArchiveHeapLoader::is_in_use(), "must be");
1282 if (_root_segments == nullptr) {
1283 _root_segments = new GrowableArrayCHeap<OopHandle, mtClassShared>(10);
1284 }
1285 _root_segments->push(OopHandle(Universe::vm_global(), segment_oop));
1286 }
1287
1288 void HeapShared::init_root_segment_sizes(int max_size_elems) {
1289 _root_segment_max_size_elems = max_size_elems;
1290 }
1291
1292 void HeapShared::serialize_tables(SerializeClosure* soc) {
1293
1294 #ifndef PRODUCT
1295 soc->do_ptr(&_archived_ArchiveHeapTestClass);
1296 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
1297 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
1298 setup_test_class(_test_class_name);
1299 }
1300 #endif
1301
1302 _run_time_subgraph_info_table.serialize_header(soc);
1303 soc->do_ptr(&_run_time_special_subgraph);
1304 }
1305
1306 static void verify_the_heap(Klass* k, const char* which) {
1307 if (VerifyArchivedFields > 0) {
1308 ResourceMark rm;
1309 log_info(aot, heap)("Verify heap %s initializing static field(s) in %s",
1310 which, k->external_name());
1311
1312 VM_Verify verify_op;
1313 VMThread::execute(&verify_op);
1314
1315 if (VerifyArchivedFields > 1 && is_init_completed()) {
1316 // At this time, the oop->klass() of some archived objects in the heap may not
1317 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
1318 // have enough information (object size, oop maps, etc) so that a GC can be safely
1319 // performed.
1320 //
1321 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
1322 // to check for GC safety.
1323 log_info(aot, heap)("Trigger GC %s initializing static field(s) in %s",
1324 which, k->external_name());
1325 FlagSetting fs1(VerifyBeforeGC, true);
1326 FlagSetting fs2(VerifyDuringGC, true);
1327 FlagSetting fs3(VerifyAfterGC, true);
1328 Universe::heap()->collect(GCCause::_java_lang_system_gc);
1329 }
1330 }
1331 }
1332
1333 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
1334 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
1335 //
1336 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
1337 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
1338 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
1339 void HeapShared::resolve_classes(JavaThread* current) {
1340 assert(CDSConfig::is_using_archive(), "runtime only!");
1341 if (!ArchiveHeapLoader::is_in_use()) {
1342 return; // nothing to do
1343 }
1344
1345 if (!CDSConfig::is_using_aot_linked_classes()) {
1346 assert( _run_time_special_subgraph != nullptr, "must be");
1347 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1348 if (klasses != nullptr) {
1349 for (int i = 0; i < klasses->length(); i++) {
1350 Klass* k = klasses->at(i);
1351 ExceptionMark em(current); // no exception can happen here
1352 resolve_or_init(k, /*do_init*/false, current);
1353 }
1354 }
1355 }
1356
1357 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
1358 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
1359 }
1360
1361 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
1362 for (int i = 0; fields[i].valid(); i++) {
1363 ArchivableStaticFieldInfo* info = &fields[i];
1364 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1365 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
1366 assert(k != nullptr && k->defined_by_boot_loader(), "sanity");
1367 resolve_classes_for_subgraph_of(current, k);
1368 }
1369 }
1370
1371 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
1372 JavaThread* THREAD = current;
1373 ExceptionMark em(THREAD);
1374 const ArchivedKlassSubGraphInfoRecord* record =
1375 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
1376 if (HAS_PENDING_EXCEPTION) {
1377 CLEAR_PENDING_EXCEPTION;
1378 }
1379 if (record == nullptr) {
1380 clear_archived_roots_of(k);
1381 }
1382 }
1383
1384 void HeapShared::initialize_java_lang_invoke(TRAPS) {
1385 if (CDSConfig::is_using_aot_linked_classes() || CDSConfig::is_dumping_method_handles()) {
1386 resolve_or_init("java/lang/invoke/Invokers$Holder", true, CHECK);
1387 resolve_or_init("java/lang/invoke/MethodHandle", true, CHECK);
1388 resolve_or_init("java/lang/invoke/MethodHandleNatives", true, CHECK);
1389 resolve_or_init("java/lang/invoke/DirectMethodHandle$Holder", true, CHECK);
1390 resolve_or_init("java/lang/invoke/DelegatingMethodHandle$Holder", true, CHECK);
1391 resolve_or_init("java/lang/invoke/LambdaForm$Holder", true, CHECK);
1392 resolve_or_init("java/lang/invoke/BoundMethodHandle$Species_L", true, CHECK);
1393 }
1394 }
1395
1396 // Initialize the InstanceKlasses of objects that are reachable from the following roots:
1397 // - interned strings
1398 // - Klass::java_mirror() -- including aot-initialized mirrors such as those of Enum klasses.
1399 // - ConstantPool::resolved_references()
1400 // - Universe::<xxx>_exception_instance()
1401 //
1402 // For example, if this enum class is initialized at AOT cache assembly time:
1403 //
1404 // enum Fruit {
1405 // APPLE, ORANGE, BANANA;
1406 // static final Set<Fruit> HAVE_SEEDS = new HashSet<>(Arrays.asList(APPLE, ORANGE));
1407 // }
1408 //
1409 // the aot-initialized mirror of Fruit has a static field that references HashSet, which
1410 // should be initialized before any Java code can access the Fruit class. Note that
1411 // HashSet itself doesn't necessary need to be an aot-initialized class.
1412 void HeapShared::init_classes_for_special_subgraph(Handle class_loader, TRAPS) {
1413 if (!ArchiveHeapLoader::is_in_use()) {
1414 return;
1415 }
1416
1417 assert( _run_time_special_subgraph != nullptr, "must be");
1418 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1419 if (klasses != nullptr) {
1420 for (int pass = 0; pass < 2; pass ++) {
1421 for (int i = 0; i < klasses->length(); i++) {
1422 Klass* k = klasses->at(i);
1423 if (k->class_loader_data() == nullptr) {
1424 // This class is not yet loaded. We will initialize it in a later phase.
1425 // For example, we have loaded only AOTLinkedClassCategory::BOOT1 classes
1426 // but k is part of AOTLinkedClassCategory::BOOT2.
1427 continue;
1428 }
1429 if (k->class_loader() == class_loader()) {
1430 if (pass == 0) {
1431 if (k->is_instance_klass()) {
1432 InstanceKlass::cast(k)->link_class(CHECK);
1433 }
1434 } else {
1435 resolve_or_init(k, /*do_init*/true, CHECK);
1436 }
1437 }
1438 }
1439 }
1440 }
1441 }
1442
1443 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
1444 JavaThread* THREAD = current;
1445 if (!ArchiveHeapLoader::is_in_use()) {
1446 return; // nothing to do
1447 }
1448
1449 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") &&
1450 !CDSConfig::is_using_optimized_module_handling() &&
1451 // archive was created with --module-path
1452 AOTClassLocationConfig::runtime()->num_module_paths() > 0) {
1453 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path.
1454 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it.
1455 log_info(aot, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d",
1456 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()),
1457 AOTClassLocationConfig::runtime()->num_module_paths());
1458 return;
1459 }
1460
1461 ExceptionMark em(THREAD);
1462 const ArchivedKlassSubGraphInfoRecord* record =
1463 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
1464
1465 if (HAS_PENDING_EXCEPTION) {
1466 CLEAR_PENDING_EXCEPTION;
1467 // None of the field value will be set if there was an exception when initializing the classes.
1468 // The java code will not see any of the archived objects in the
1469 // subgraphs referenced from k in this case.
1470 return;
1471 }
1472
1473 if (record != nullptr) {
1474 init_archived_fields_for(k, record);
1475 }
1476 }
1477
1478 const ArchivedKlassSubGraphInfoRecord*
1479 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
1480 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
1481
1482 if (!k->in_aot_cache()) {
1483 return nullptr;
1484 }
1485 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1486 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1487
1488 #ifndef PRODUCT
1489 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
1490 _test_class = k;
1491 _test_class_record = record;
1492 }
1493 #endif
1494
1495 // Initialize from archived data. Currently this is done only
1496 // during VM initialization time. No lock is needed.
1497 if (record == nullptr) {
1498 if (log_is_enabled(Info, aot, heap)) {
1499 ResourceMark rm(THREAD);
1500 log_info(aot, heap)("subgraph %s is not recorded",
1501 k->external_name());
1502 }
1503 return nullptr;
1504 } else {
1505 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
1506 if (log_is_enabled(Info, aot, heap)) {
1507 ResourceMark rm(THREAD);
1508 log_info(aot, heap)("subgraph %s cannot be used because full module graph is disabled",
1509 k->external_name());
1510 }
1511 return nullptr;
1512 }
1513
1514 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
1515 if (log_is_enabled(Info, aot, heap)) {
1516 ResourceMark rm(THREAD);
1517 log_info(aot, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
1518 k->external_name());
1519 }
1520 return nullptr;
1521 }
1522
1523 if (log_is_enabled(Info, aot, heap)) {
1524 ResourceMark rm;
1525 log_info(aot, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
1526 }
1527
1528 resolve_or_init(k, do_init, CHECK_NULL);
1529
1530 // Load/link/initialize the klasses of the objects in the subgraph.
1531 // nullptr class loader is used.
1532 Array<Klass*>* klasses = record->subgraph_object_klasses();
1533 if (klasses != nullptr) {
1534 for (int i = 0; i < klasses->length(); i++) {
1535 Klass* klass = klasses->at(i);
1536 if (!klass->in_aot_cache()) {
1537 return nullptr;
1538 }
1539 resolve_or_init(klass, do_init, CHECK_NULL);
1540 }
1541 }
1542 }
1543
1544 return record;
1545 }
1546
1547 void HeapShared::resolve_or_init(const char* klass_name, bool do_init, TRAPS) {
1548 TempNewSymbol klass_name_sym = SymbolTable::new_symbol(klass_name);
1549 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name_sym);
1550 if (k == nullptr) {
1551 return;
1552 }
1553 assert(k->defined_by_boot_loader(), "sanity");
1554 resolve_or_init(k, false, CHECK);
1555 if (do_init) {
1556 resolve_or_init(k, true, CHECK);
1557 }
1558 }
1559
1560 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1561 if (!do_init) {
1562 if (k->class_loader_data() == nullptr) {
1563 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1564 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1565 }
1566 } else {
1567 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
1568 if (k->is_instance_klass()) {
1569 InstanceKlass* ik = InstanceKlass::cast(k);
1570 ik->initialize(CHECK);
1571 } else if (k->is_objArray_klass()) {
1572 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1573 oak->initialize(CHECK);
1574 }
1575 }
1576 }
1577
1578 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1579 verify_the_heap(k, "before");
1580
1581 // Load the subgraph entry fields from the record and store them back to
1582 // the corresponding fields within the mirror.
1583 oop m = k->java_mirror();
1584 Array<int>* entry_field_records = record->entry_field_records();
1585 if (entry_field_records != nullptr) {
1586 int efr_len = entry_field_records->length();
1587 assert(efr_len % 2 == 0, "sanity");
1588 for (int i = 0; i < efr_len; i += 2) {
1589 int field_offset = entry_field_records->at(i);
1590 int root_index = entry_field_records->at(i+1);
1591 oop v = get_root(root_index, /*clear=*/true);
1592 if (k->has_aot_initialized_mirror()) {
1593 assert(v == m->obj_field(field_offset), "must be aot-initialized");
1594 } else {
1595 m->obj_field_put(field_offset, v);
1596 }
1597 log_debug(aot, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1598 }
1599
1600 // Done. Java code can see the archived sub-graphs referenced from k's
1601 // mirror after this point.
1602 if (log_is_enabled(Info, aot, heap)) {
1603 ResourceMark rm;
1604 log_info(aot, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s%s",
1605 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "",
1606 k->has_aot_initialized_mirror() ? " (aot-inited)" : "");
1607 }
1608 }
1609
1610 verify_the_heap(k, "after ");
1611 }
1612
1613 void HeapShared::clear_archived_roots_of(Klass* k) {
1614 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1615 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1616 if (record != nullptr) {
1617 Array<int>* entry_field_records = record->entry_field_records();
1618 if (entry_field_records != nullptr) {
1619 int efr_len = entry_field_records->length();
1620 assert(efr_len % 2 == 0, "sanity");
1621 for (int i = 0; i < efr_len; i += 2) {
1622 int root_index = entry_field_records->at(i+1);
1623 clear_root(root_index);
1624 }
1625 }
1626 }
1627 }
1628
1629 // Push all oop fields (or oop array elemenets in case of an objArray) in
1630 // _referencing_obj onto the _stack.
1631 class HeapShared::OopFieldPusher: public BasicOopIterateClosure {
1632 PendingOopStack* _stack;
1633 GrowableArray<oop> _found_oop_fields;
1634 int _level;
1635 bool _record_klasses_only;
1636 KlassSubGraphInfo* _subgraph_info;
1637 oop _referencing_obj;
1638 bool _is_java_lang_ref;
1639 public:
1640 OopFieldPusher(PendingOopStack* stack,
1641 int level,
1642 bool record_klasses_only,
1643 KlassSubGraphInfo* subgraph_info,
1644 oop orig) :
1645 _stack(stack),
1646 _found_oop_fields(),
1647 _level(level),
1648 _record_klasses_only(record_klasses_only),
1649 _subgraph_info(subgraph_info),
1650 _referencing_obj(orig) {
1651 _is_java_lang_ref = AOTReferenceObjSupport::check_if_ref_obj(orig);
1652 }
1653 void do_oop(narrowOop *p) { OopFieldPusher::do_oop_work(p); }
1654 void do_oop( oop *p) { OopFieldPusher::do_oop_work(p); }
1655
1656 ~OopFieldPusher() {
1657 while (_found_oop_fields.length() > 0) {
1658 // This produces the exact same traversal order as the previous version
1659 // of OopFieldPusher that recurses on the C stack -- a depth-first search,
1660 // walking the oop fields in _referencing_obj by ascending field offsets.
1661 oop obj = _found_oop_fields.pop();
1662 _stack->push(PendingOop(obj, _referencing_obj, _level + 1));
1663 }
1664 }
1665
1666 protected:
1667 template <class T> void do_oop_work(T *p) {
1668 int field_offset = pointer_delta_as_int((char*)p, cast_from_oop<char*>(_referencing_obj));
1669 oop obj = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(_referencing_obj, field_offset);
1670 if (!CompressedOops::is_null(obj)) {
1671 if (_is_java_lang_ref && AOTReferenceObjSupport::skip_field(field_offset)) {
1672 // Do not follow these fields. They will be cleared to null.
1673 return;
1674 }
1675
1676 if (!_record_klasses_only && log_is_enabled(Debug, aot, heap)) {
1677 ResourceMark rm;
1678 log_debug(aot, heap)("(%d) %s[%d] ==> " PTR_FORMAT " size %zu %s", _level,
1679 _referencing_obj->klass()->external_name(), field_offset,
1680 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1681 if (log_is_enabled(Trace, aot, heap)) {
1682 LogTarget(Trace, aot, heap) log;
1683 LogStream out(log);
1684 obj->print_on(&out);
1685 }
1686 }
1687
1688 _found_oop_fields.push(obj);
1689 }
1690 }
1691
1692 public:
1693 oop referencing_obj() { return _referencing_obj; }
1694 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1695 };
1696
1697 // Checks if an oop has any non-null oop fields
1698 class PointsToOopsChecker : public BasicOopIterateClosure {
1699 bool _result;
1700
1701 template <class T> void check(T *p) {
1702 _result |= (HeapAccess<>::oop_load(p) != nullptr);
1703 }
1704
1705 public:
1706 PointsToOopsChecker() : _result(false) {}
1707 void do_oop(narrowOop *p) { check(p); }
1708 void do_oop( oop *p) { check(p); }
1709 bool result() { return _result; }
1710 };
1711
1712 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj, oop referrer) {
1713 PointsToOopsChecker points_to_oops_checker;
1714 obj->oop_iterate(&points_to_oops_checker);
1715 return CachedOopInfo(OopHandle(Universe::vm_global(), referrer), points_to_oops_checker.result());
1716 }
1717
1718 void HeapShared::init_box_classes(TRAPS) {
1719 if (ArchiveHeapLoader::is_in_use()) {
1720 vmClasses::Boolean_klass()->initialize(CHECK);
1721 vmClasses::Character_klass()->initialize(CHECK);
1722 vmClasses::Float_klass()->initialize(CHECK);
1723 vmClasses::Double_klass()->initialize(CHECK);
1724 vmClasses::Byte_klass()->initialize(CHECK);
1725 vmClasses::Short_klass()->initialize(CHECK);
1726 vmClasses::Integer_klass()->initialize(CHECK);
1727 vmClasses::Long_klass()->initialize(CHECK);
1728 vmClasses::Void_klass()->initialize(CHECK);
1729 }
1730 }
1731
1732 void HeapShared::exit_on_error() {
1733 if (_context != nullptr) {
1734 ResourceMark rm;
1735 LogStream ls(Log(cds, heap)::error());
1736 ls.print_cr("Context");
1737 for (int i = 0; i < _context->length(); i++) {
1738 const char* s = _context->at(i);
1739 ls.print_cr("- %s", s);
1740 }
1741 }
1742 debug_trace();
1743 AOTMetaspace::unrecoverable_writing_error();
1744 }
1745
1746 // (1) If orig_obj has not been archived yet, archive it.
1747 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1748 // trace all objects that are reachable from it, and make sure these objects are archived.
1749 // (3) Record the klasses of all objects that are reachable from orig_obj (including those that
1750 // were already archived when this function is called)
1751 bool HeapShared::archive_reachable_objects_from(int level,
1752 KlassSubGraphInfo* subgraph_info,
1753 oop orig_obj) {
1754 assert(orig_obj != nullptr, "must be");
1755 PendingOopStack stack;
1756 stack.push(PendingOop(orig_obj, nullptr, level));
1757
1758 while (stack.length() > 0) {
1759 PendingOop po = stack.pop();
1760 _object_being_archived = po;
1761 bool status = walk_one_object(&stack, po.level(), subgraph_info, po.obj(), po.referrer());
1762 _object_being_archived = PendingOop();
1763
1764 if (!status) {
1765 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1766 // as the Java code will take care of initializing this field dynamically.
1767 assert(level == 1, "VM should have exited with unarchivable objects for _level > 1");
1768 return false;
1769 }
1770 }
1771
1772 return true;
1773 }
1774
1775 bool HeapShared::walk_one_object(PendingOopStack* stack, int level, KlassSubGraphInfo* subgraph_info,
1776 oop orig_obj, oop referrer) {
1777 assert(orig_obj != nullptr, "must be");
1778 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1779 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1780 // If you get an error here, you probably made a change in the JDK library that has added
1781 // these objects that are referenced (directly or indirectly) by static fields.
1782 ResourceMark rm;
1783 log_error(aot, heap)("Cannot archive object " PTR_FORMAT " of class %s", p2i(orig_obj), orig_obj->klass()->external_name());
1784 debug_trace();
1785 AOTMetaspace::unrecoverable_writing_error();
1786 }
1787
1788 if (log_is_enabled(Debug, aot, heap) && java_lang_Class::is_instance(orig_obj)) {
1789 ResourceMark rm;
1790 LogTarget(Debug, aot, heap) log;
1791 LogStream out(log);
1792 out.print("Found java mirror " PTR_FORMAT " ", p2i(orig_obj));
1793 Klass* k = java_lang_Class::as_Klass(orig_obj);
1794 if (k != nullptr) {
1795 out.print("%s", k->external_name());
1796 } else {
1797 out.print("primitive");
1798 }
1799 out.print_cr("; scratch mirror = " PTR_FORMAT,
1800 p2i(scratch_java_mirror(orig_obj)));
1801 }
1802
1803 if (java_lang_Class::is_instance(orig_obj)) {
1804 Klass* k = java_lang_Class::as_Klass(orig_obj);
1805 if (RegeneratedClasses::has_been_regenerated(k)) {
1806 orig_obj = RegeneratedClasses::get_regenerated_object(k)->java_mirror();
1807 }
1808 }
1809
1810 if (CDSConfig::is_initing_classes_at_dump_time()) {
1811 if (java_lang_Class::is_instance(orig_obj)) {
1812 orig_obj = scratch_java_mirror(orig_obj);
1813 assert(orig_obj != nullptr, "must be archived");
1814 }
1815 } else if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _dump_time_special_subgraph) {
1816 // Without CDSConfig::is_initing_classes_at_dump_time(), we only allow archived objects to
1817 // point to the mirrors of (1) j.l.Object, (2) primitive classes, and (3) box classes. These are initialized
1818 // very early by HeapShared::init_box_classes().
1819 if (orig_obj == vmClasses::Object_klass()->java_mirror()
1820 || java_lang_Class::is_primitive(orig_obj)
1821 || orig_obj == vmClasses::Boolean_klass()->java_mirror()
1822 || orig_obj == vmClasses::Character_klass()->java_mirror()
1823 || orig_obj == vmClasses::Float_klass()->java_mirror()
1824 || orig_obj == vmClasses::Double_klass()->java_mirror()
1825 || orig_obj == vmClasses::Byte_klass()->java_mirror()
1826 || orig_obj == vmClasses::Short_klass()->java_mirror()
1827 || orig_obj == vmClasses::Integer_klass()->java_mirror()
1828 || orig_obj == vmClasses::Long_klass()->java_mirror()
1829 || orig_obj == vmClasses::Void_klass()->java_mirror()) {
1830 orig_obj = scratch_java_mirror(orig_obj);
1831 assert(orig_obj != nullptr, "must be archived");
1832 } else {
1833 // If you get an error here, you probably made a change in the JDK library that has added a Class
1834 // object that is referenced (directly or indirectly) by an ArchivableStaticFieldInfo
1835 // defined at the top of this file.
1836 log_error(aot, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1837 debug_trace();
1838 AOTMetaspace::unrecoverable_writing_error();
1839 }
1840 }
1841
1842 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1843 // orig_obj has already been archived and traced. Nothing more to do.
1844 return true;
1845 } else {
1846 set_has_been_seen_during_subgraph_recording(orig_obj);
1847 }
1848
1849 bool already_archived = has_been_archived(orig_obj);
1850 bool record_klasses_only = already_archived;
1851 if (!already_archived) {
1852 ++_num_new_archived_objs;
1853 if (!archive_object(orig_obj, referrer, subgraph_info)) {
1854 // Skip archiving the sub-graph referenced from the current entry field.
1855 ResourceMark rm;
1856 log_error(aot, heap)(
1857 "Cannot archive the sub-graph referenced from %s object ("
1858 PTR_FORMAT ") size %zu, skipped.",
1859 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1860 if (level == 1) {
1861 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1862 // as the Java code will take care of initializing this field dynamically.
1863 return false;
1864 } else {
1865 // We don't know how to handle an object that has been archived, but some of its reachable
1866 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1867 // we have a real use case.
1868 AOTMetaspace::unrecoverable_writing_error();
1869 }
1870 }
1871 }
1872
1873 Klass *orig_k = orig_obj->klass();
1874 subgraph_info->add_subgraph_object_klass(orig_k);
1875
1876 {
1877 // Find all the oops that are referenced by orig_obj, push them onto the stack
1878 // so we can work on them next.
1879 ResourceMark rm;
1880 OopFieldPusher pusher(stack, level, record_klasses_only, subgraph_info, orig_obj);
1881 orig_obj->oop_iterate(&pusher);
1882 }
1883
1884 if (CDSConfig::is_initing_classes_at_dump_time()) {
1885 // The enum klasses are archived with aot-initialized mirror.
1886 // See AOTClassInitializer::can_archive_initialized_mirror().
1887 } else {
1888 if (CDSEnumKlass::is_enum_obj(orig_obj)) {
1889 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj);
1890 }
1891 }
1892
1893 return true;
1894 }
1895
1896 //
1897 // Start from the given static field in a java mirror and archive the
1898 // complete sub-graph of java heap objects that are reached directly
1899 // or indirectly from the starting object by following references.
1900 // Sub-graph archiving restrictions (current):
1901 //
1902 // - All classes of objects in the archived sub-graph (including the
1903 // entry class) must be boot class only.
1904 // - No java.lang.Class instance (java mirror) can be included inside
1905 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1906 //
1907 // The Java heap object sub-graph archiving process (see OopFieldPusher):
1908 //
1909 // 1) Java object sub-graph archiving starts from a given static field
1910 // within a Class instance (java mirror). If the static field is a
1911 // reference field and points to a non-null java object, proceed to
1912 // the next step.
1913 //
1914 // 2) Archives the referenced java object. If an archived copy of the
1915 // current object already exists, updates the pointer in the archived
1916 // copy of the referencing object to point to the current archived object.
1917 // Otherwise, proceed to the next step.
1918 //
1919 // 3) Follows all references within the current java object and recursively
1920 // archive the sub-graph of objects starting from each reference.
1921 //
1922 // 4) Updates the pointer in the archived copy of referencing object to
1923 // point to the current archived object.
1924 //
1925 // 5) The Klass of the current java object is added to the list of Klasses
1926 // for loading and initializing before any object in the archived graph can
1927 // be accessed at runtime.
1928 //
1929 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1930 const char* klass_name,
1931 int field_offset,
1932 const char* field_name) {
1933 assert(CDSConfig::is_dumping_heap(), "dump time only");
1934 assert(k->defined_by_boot_loader(), "must be boot class");
1935
1936 oop m = k->java_mirror();
1937
1938 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1939 oop f = m->obj_field(field_offset);
1940
1941 log_debug(aot, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1942
1943 if (!CompressedOops::is_null(f)) {
1944 if (log_is_enabled(Trace, aot, heap)) {
1945 LogTarget(Trace, aot, heap) log;
1946 LogStream out(log);
1947 f->print_on(&out);
1948 }
1949
1950 bool success = archive_reachable_objects_from(1, subgraph_info, f);
1951 if (!success) {
1952 log_error(aot, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1953 klass_name, field_name);
1954 } else {
1955 // Note: the field value is not preserved in the archived mirror.
1956 // Record the field as a new subGraph entry point. The recorded
1957 // information is restored from the archive at runtime.
1958 subgraph_info->add_subgraph_entry_field(field_offset, f);
1959 log_info(aot, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
1960 }
1961 } else {
1962 // The field contains null, we still need to record the entry point,
1963 // so it can be restored at runtime.
1964 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
1965 }
1966 }
1967
1968 #ifndef PRODUCT
1969 class VerifySharedOopClosure: public BasicOopIterateClosure {
1970 public:
1971 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1972 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1973
1974 protected:
1975 template <class T> void do_oop_work(T *p) {
1976 oop obj = RawAccess<>::oop_load(p);
1977 if (!CompressedOops::is_null(obj)) {
1978 HeapShared::verify_reachable_objects_from(obj);
1979 }
1980 }
1981 };
1982
1983 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1984 assert(CDSConfig::is_dumping_heap(), "dump time only");
1985 assert(k->defined_by_boot_loader(), "must be boot class");
1986
1987 oop m = k->java_mirror();
1988 oop f = m->obj_field(field_offset);
1989 if (!CompressedOops::is_null(f)) {
1990 verify_subgraph_from(f);
1991 }
1992 }
1993
1994 void HeapShared::verify_subgraph_from(oop orig_obj) {
1995 if (!has_been_archived(orig_obj)) {
1996 // It's OK for the root of a subgraph to be not archived. See comments in
1997 // archive_reachable_objects_from().
1998 return;
1999 }
2000
2001 // Verify that all objects reachable from orig_obj are archived.
2002 init_seen_objects_table();
2003 verify_reachable_objects_from(orig_obj);
2004 delete_seen_objects_table();
2005 }
2006
2007 void HeapShared::verify_reachable_objects_from(oop obj) {
2008 _num_total_verifications ++;
2009 if (java_lang_Class::is_instance(obj)) {
2010 Klass* k = java_lang_Class::as_Klass(obj);
2011 if (RegeneratedClasses::has_been_regenerated(k)) {
2012 k = RegeneratedClasses::get_regenerated_object(k);
2013 obj = k->java_mirror();
2014 }
2015 obj = scratch_java_mirror(obj);
2016 assert(obj != nullptr, "must be");
2017 }
2018 if (!has_been_seen_during_subgraph_recording(obj)) {
2019 set_has_been_seen_during_subgraph_recording(obj);
2020 assert(has_been_archived(obj), "must be");
2021 VerifySharedOopClosure walker;
2022 obj->oop_iterate(&walker);
2023 }
2024 }
2025 #endif
2026
2027 void HeapShared::check_special_subgraph_classes() {
2028 if (CDSConfig::is_initing_classes_at_dump_time()) {
2029 // We can have aot-initialized classes (such as Enums) that can reference objects
2030 // of arbitrary types. Currently, we trust the JEP 483 implementation to only
2031 // aot-initialize classes that are "safe".
2032 //
2033 // TODO: we need an automatic tool that checks the safety of aot-initialized
2034 // classes (when we extend the set of aot-initialized classes beyond JEP 483)
2035 return;
2036 } else {
2037 // In this case, the special subgraph should contain a few specific types
2038 GrowableArray<Klass*>* klasses = _dump_time_special_subgraph->subgraph_object_klasses();
2039 int num = klasses->length();
2040 for (int i = 0; i < num; i++) {
2041 Klass* subgraph_k = klasses->at(i);
2042 Symbol* name = subgraph_k->name();
2043 if (subgraph_k->is_instance_klass() &&
2044 name != vmSymbols::java_lang_Class() &&
2045 name != vmSymbols::java_lang_String() &&
2046 name != vmSymbols::java_lang_ArithmeticException() &&
2047 name != vmSymbols::java_lang_ArrayIndexOutOfBoundsException() &&
2048 name != vmSymbols::java_lang_ArrayStoreException() &&
2049 name != vmSymbols::java_lang_ClassCastException() &&
2050 name != vmSymbols::java_lang_InternalError() &&
2051 name != vmSymbols::java_lang_NullPointerException()) {
2052 ResourceMark rm;
2053 fatal("special subgraph cannot have objects of type %s", subgraph_k->external_name());
2054 }
2055 }
2056 }
2057 }
2058
2059 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
2060 HeapShared::PendingOop HeapShared::_object_being_archived;
2061 int HeapShared::_num_new_walked_objs;
2062 int HeapShared::_num_new_archived_objs;
2063 int HeapShared::_num_old_recorded_klasses;
2064
2065 int HeapShared::_num_total_subgraph_recordings = 0;
2066 int HeapShared::_num_total_walked_objs = 0;
2067 int HeapShared::_num_total_archived_objs = 0;
2068 int HeapShared::_num_total_recorded_klasses = 0;
2069 int HeapShared::_num_total_verifications = 0;
2070
2071 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
2072 return _seen_objects_table->get(obj) != nullptr;
2073 }
2074
2075 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
2076 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
2077 _seen_objects_table->put_when_absent(obj, true);
2078 _seen_objects_table->maybe_grow();
2079 ++ _num_new_walked_objs;
2080 }
2081
2082 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
2083 log_info(aot, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
2084 init_subgraph_info(k, is_full_module_graph);
2085 init_seen_objects_table();
2086 _num_new_walked_objs = 0;
2087 _num_new_archived_objs = 0;
2088 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
2089 }
2090
2091 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
2092 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
2093 _num_old_recorded_klasses;
2094 log_info(aot, heap)("Done recording subgraph(s) for archived fields in %s: "
2095 "walked %d objs, archived %d new objs, recorded %d classes",
2096 class_name, _num_new_walked_objs, _num_new_archived_objs,
2097 num_new_recorded_klasses);
2098
2099 delete_seen_objects_table();
2100
2101 _num_total_subgraph_recordings ++;
2102 _num_total_walked_objs += _num_new_walked_objs;
2103 _num_total_archived_objs += _num_new_archived_objs;
2104 _num_total_recorded_klasses += num_new_recorded_klasses;
2105 }
2106
2107 class ArchivableStaticFieldFinder: public FieldClosure {
2108 InstanceKlass* _ik;
2109 Symbol* _field_name;
2110 bool _found;
2111 int _offset;
2112 public:
2113 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
2114 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
2115
2116 virtual void do_field(fieldDescriptor* fd) {
2117 if (fd->name() == _field_name) {
2118 assert(!_found, "fields can never be overloaded");
2119 if (is_reference_type(fd->field_type())) {
2120 _found = true;
2121 _offset = fd->offset();
2122 }
2123 }
2124 }
2125 bool found() { return _found; }
2126 int offset() { return _offset; }
2127 };
2128
2129 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
2130 TRAPS) {
2131 for (int i = 0; fields[i].valid(); i++) {
2132 ArchivableStaticFieldInfo* info = &fields[i];
2133 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
2134 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
2135 ResourceMark rm; // for stringStream::as_string() etc.
2136
2137 #ifndef PRODUCT
2138 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
2139 const char* test_class_name = ArchiveHeapTestClass;
2140 #else
2141 bool is_test_class = false;
2142 const char* test_class_name = ""; // avoid C++ printf checks warnings.
2143 #endif
2144
2145 if (is_test_class) {
2146 log_warning(aot)("Loading ArchiveHeapTestClass %s ...", test_class_name);
2147 }
2148
2149 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
2150 if (HAS_PENDING_EXCEPTION) {
2151 CLEAR_PENDING_EXCEPTION;
2152 stringStream st;
2153 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
2154 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2155 }
2156
2157 if (!k->is_instance_klass()) {
2158 stringStream st;
2159 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
2160 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2161 }
2162
2163 InstanceKlass* ik = InstanceKlass::cast(k);
2164 assert(InstanceKlass::cast(ik)->defined_by_boot_loader(),
2165 "Only support boot classes");
2166
2167 if (is_test_class) {
2168 if (ik->module()->is_named()) {
2169 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
2170 // core-lib classes. You need to at least append to the bootclasspath.
2171 stringStream st;
2172 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name);
2173 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2174 }
2175
2176 if (ik->package() != nullptr) {
2177 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
2178 stringStream st;
2179 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name);
2180 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2181 }
2182 } else {
2183 if (ik->module()->name() != vmSymbols::java_base()) {
2184 // We don't want to deal with cases when a module is unavailable at runtime.
2185 // FUTURE -- load from archived heap only when module graph has not changed
2186 // between dump and runtime.
2187 stringStream st;
2188 st.print("%s is not in java.base module", info->klass_name);
2189 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2190 }
2191 }
2192
2193 if (is_test_class) {
2194 log_warning(aot)("Initializing ArchiveHeapTestClass %s ...", test_class_name);
2195 }
2196 ik->initialize(CHECK);
2197
2198 ArchivableStaticFieldFinder finder(ik, field_name);
2199 ik->do_local_static_fields(&finder);
2200 if (!finder.found()) {
2201 stringStream st;
2202 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
2203 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2204 }
2205
2206 info->klass = ik;
2207 info->offset = finder.offset();
2208 }
2209 }
2210
2211 void HeapShared::init_subgraph_entry_fields(TRAPS) {
2212 assert(CDSConfig::is_dumping_heap(), "must be");
2213 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
2214 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
2215 if (CDSConfig::is_dumping_full_module_graph()) {
2216 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
2217 }
2218 }
2219
2220 #ifndef PRODUCT
2221 void HeapShared::setup_test_class(const char* test_class_name) {
2222 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
2223 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
2224 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
2225 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
2226
2227 if (test_class_name != nullptr) {
2228 p[num_slots - 2].klass_name = test_class_name;
2229 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
2230 }
2231 }
2232
2233 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
2234 // during runtime. This may be called before the module system is initialized so
2235 // we cannot rely on InstanceKlass::module(), etc.
2236 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
2237 if (_test_class != nullptr) {
2238 if (ik == _test_class) {
2239 return true;
2240 }
2241 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
2242 if (klasses == nullptr) {
2243 return false;
2244 }
2245
2246 for (int i = 0; i < klasses->length(); i++) {
2247 Klass* k = klasses->at(i);
2248 if (k == ik) {
2249 Symbol* name;
2250 if (k->is_instance_klass()) {
2251 name = InstanceKlass::cast(k)->name();
2252 } else if (k->is_objArray_klass()) {
2253 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
2254 if (!bk->is_instance_klass()) {
2255 return false;
2256 }
2257 name = bk->name();
2258 } else {
2259 return false;
2260 }
2261
2262 // See KlassSubGraphInfo::check_allowed_klass() - we only allow test classes
2263 // to be:
2264 // (A) java.base classes (which must not be in the unnamed module)
2265 // (B) test classes which must be in the unnamed package of the unnamed module.
2266 // So if we see a '/' character in the class name, it must be in (A);
2267 // otherwise it must be in (B).
2268 if (name->index_of_at(0, "/", 1) >= 0) {
2269 return false; // (A)
2270 }
2271
2272 return true; // (B)
2273 }
2274 }
2275 }
2276
2277 return false;
2278 }
2279
2280 void HeapShared::initialize_test_class_from_archive(JavaThread* current) {
2281 Klass* k = _test_class;
2282 if (k != nullptr && ArchiveHeapLoader::is_in_use()) {
2283 JavaThread* THREAD = current;
2284 ExceptionMark em(THREAD);
2285 const ArchivedKlassSubGraphInfoRecord* record =
2286 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
2287
2288 // The _test_class is in the unnamed module, so it can't call CDS.initializeFromArchive()
2289 // from its <clinit> method. So we set up its "archivedObjects" field first, before
2290 // calling its <clinit>. This is not strictly clean, but it's a convenient way to write unit
2291 // test cases (see test/hotspot/jtreg/runtime/cds/appcds/cacheObject/ArchiveHeapTestClass.java).
2292 if (record != nullptr) {
2293 init_archived_fields_for(k, record);
2294 }
2295 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
2296 }
2297 }
2298 #endif
2299
2300 void HeapShared::init_for_dumping(TRAPS) {
2301 if (CDSConfig::is_dumping_heap()) {
2302 setup_test_class(ArchiveHeapTestClass);
2303 _dumped_interned_strings = new (mtClass)DumpedInternedStrings(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
2304 init_subgraph_entry_fields(CHECK);
2305 }
2306 }
2307
2308 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
2309 bool is_full_module_graph) {
2310 _num_total_subgraph_recordings = 0;
2311 _num_total_walked_objs = 0;
2312 _num_total_archived_objs = 0;
2313 _num_total_recorded_klasses = 0;
2314 _num_total_verifications = 0;
2315
2316 // For each class X that has one or more archived fields:
2317 // [1] Dump the subgraph of each archived field
2318 // [2] Create a list of all the class of the objects that can be reached
2319 // by any of these static fields.
2320 // At runtime, these classes are initialized before X's archived fields
2321 // are restored by HeapShared::initialize_from_archived_subgraph().
2322 for (int i = 0; fields[i].valid(); ) {
2323 ArchivableStaticFieldInfo* info = &fields[i];
2324 const char* klass_name = info->klass_name;
2325 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
2326
2327 ContextMark cm(klass_name);
2328 // If you have specified consecutive fields of the same klass in
2329 // fields[], these will be archived in the same
2330 // {start_recording_subgraph ... done_recording_subgraph} pass to
2331 // save time.
2332 for (; fields[i].valid(); i++) {
2333 ArchivableStaticFieldInfo* f = &fields[i];
2334 if (f->klass_name != klass_name) {
2335 break;
2336 }
2337
2338 ContextMark cm(f->field_name);
2339 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
2340 f->offset, f->field_name);
2341 }
2342 done_recording_subgraph(info->klass, klass_name);
2343 }
2344
2345 log_info(aot, heap)("Archived subgraph records = %d",
2346 _num_total_subgraph_recordings);
2347 log_info(aot, heap)(" Walked %d objects", _num_total_walked_objs);
2348 log_info(aot, heap)(" Archived %d objects", _num_total_archived_objs);
2349 log_info(aot, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
2350
2351 #ifndef PRODUCT
2352 for (int i = 0; fields[i].valid(); i++) {
2353 ArchivableStaticFieldInfo* f = &fields[i];
2354 verify_subgraph_from_static_field(f->klass, f->offset);
2355 }
2356 log_info(aot, heap)(" Verified %d references", _num_total_verifications);
2357 #endif
2358 }
2359
2360 // Keep track of the contents of the archived interned string table. This table
2361 // is used only by CDSHeapVerifier.
2362 void HeapShared::add_to_dumped_interned_strings(oop string) {
2363 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
2364 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(string), "must be");
2365 bool created;
2366 _dumped_interned_strings->put_if_absent(string, true, &created);
2367 if (created) {
2368 // Prevent string deduplication from changing the value field to
2369 // something not in the archive.
2370 java_lang_String::set_deduplication_forbidden(string);
2371 _dumped_interned_strings->maybe_grow();
2372 }
2373 }
2374
2375 bool HeapShared::is_dumped_interned_string(oop o) {
2376 return _dumped_interned_strings->get(o) != nullptr;
2377 }
2378
2379 // These tables should be used only within the CDS safepoint, so
2380 // delete them before we exit the safepoint. Otherwise the table will
2381 // contain bad oops after a GC.
2382 void HeapShared::delete_tables_with_raw_oops() {
2383 assert(_seen_objects_table == nullptr, "should have been deleted");
2384
2385 delete _dumped_interned_strings;
2386 _dumped_interned_strings = nullptr;
2387
2388 ArchiveHeapWriter::delete_tables_with_raw_oops();
2389 }
2390
2391 void HeapShared::debug_trace() {
2392 ResourceMark rm;
2393 oop referrer = _object_being_archived.referrer();
2394 if (referrer != nullptr) {
2395 LogStream ls(Log(aot, heap)::error());
2396 ls.print_cr("Reference trace");
2397 CDSHeapVerifier::trace_to_root(&ls, referrer);
2398 }
2399 }
2400
2401 #ifndef PRODUCT
2402 // At dump-time, find the location of all the non-null oop pointers in an archived heap
2403 // region. This way we can quickly relocate all the pointers without using
2404 // BasicOopIterateClosure at runtime.
2405 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
2406 void* _start;
2407 BitMap *_oopmap;
2408 int _num_total_oops;
2409 int _num_null_oops;
2410 public:
2411 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
2412 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
2413
2414 virtual void do_oop(narrowOop* p) {
2415 assert(UseCompressedOops, "sanity");
2416 _num_total_oops ++;
2417 narrowOop v = *p;
2418 if (!CompressedOops::is_null(v)) {
2419 size_t idx = p - (narrowOop*)_start;
2420 _oopmap->set_bit(idx);
2421 } else {
2422 _num_null_oops ++;
2423 }
2424 }
2425 virtual void do_oop(oop* p) {
2426 assert(!UseCompressedOops, "sanity");
2427 _num_total_oops ++;
2428 if ((*p) != nullptr) {
2429 size_t idx = p - (oop*)_start;
2430 _oopmap->set_bit(idx);
2431 } else {
2432 _num_null_oops ++;
2433 }
2434 }
2435 int num_total_oops() const { return _num_total_oops; }
2436 int num_null_oops() const { return _num_null_oops; }
2437 };
2438 #endif
2439
2440 void HeapShared::count_allocation(size_t size) {
2441 _total_obj_count ++;
2442 _total_obj_size += size;
2443 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2444 if (size <= (size_t(1) << i)) {
2445 _alloc_count[i] ++;
2446 _alloc_size[i] += size;
2447 return;
2448 }
2449 }
2450 }
2451
2452 static double avg_size(size_t size, size_t count) {
2453 double avg = 0;
2454 if (count > 0) {
2455 avg = double(size * HeapWordSize) / double(count);
2456 }
2457 return avg;
2458 }
2459
2460 void HeapShared::print_stats() {
2461 size_t huge_count = _total_obj_count;
2462 size_t huge_size = _total_obj_size;
2463
2464 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2465 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
2466 size_t count = _alloc_count[i];
2467 size_t size = _alloc_size[i];
2468 log_info(aot, heap)("%8zu objects are <= %-6zu"
2469 " bytes (total %8zu bytes, avg %8.1f bytes)",
2470 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
2471 huge_count -= count;
2472 huge_size -= size;
2473 }
2474
2475 log_info(aot, heap)("%8zu huge objects (total %8zu bytes"
2476 ", avg %8.1f bytes)",
2477 huge_count, huge_size * HeapWordSize,
2478 avg_size(huge_size, huge_count));
2479 log_info(aot, heap)("%8zu total objects (total %8zu bytes"
2480 ", avg %8.1f bytes)",
2481 _total_obj_count, _total_obj_size * HeapWordSize,
2482 avg_size(_total_obj_size, _total_obj_count));
2483 }
2484
2485 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
2486 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
2487 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle());
2488 if (k == nullptr) {
2489 return false;
2490 } else {
2491 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
2492 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
2493 fieldDescriptor fd;
2494 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
2495 oop m = k->java_mirror();
2496 oop f = m->obj_field(fd.offset());
2497 if (CompressedOops::is_null(f)) {
2498 return false;
2499 }
2500 } else {
2501 return false;
2502 }
2503 }
2504 return true;
2505 }
2506
2507 #endif // INCLUDE_CDS_JAVA_HEAP